To paraphrase Captain Kirk, "Double dumbass on this!"
I guess there's bad news and good news. The bad news is we've been deprived of the short-term satisfaction of getting the film in less than a year. The good news is that HOPEFULLY, this will give them the time to make JW:D the best possible version of the film, which a rushed production to meet a release date might have prevented.
At the very least, they can shoot scenes with the cast on Malta now - when it's safe - as opposed to shooting with only stunt doubles and second unit which they've supposedly done so far. They'll have to time iron out story issues, including reshoots, and perfect the special effects. Honestly, I wish they'd pushed JP3 back when they tossed the script 5 weeks before filming - we might have gotten a much better movie.
Remember they also pushed JW back from an original 2014 release, to 2015, and it wasn't the end of the world. Franchise Will Find a Way!
To compensate, they've also released the teaser poster, which I'm sure will hold us until 2022.